Disk coating is usually carried by methods such as dip coating, spin coating and dip-spin coating. In dip coating the disk is dipped into a coating liquid and then removed to allow excess material to drain from the disk. In spin coating, a disk is placed in a horizontal plane on a rotatable spindle. A coating liquid is applied to the upper surface of the spinning disk which is then spread across the surface of the disk by virtual centrifugal forces. In dip-spin coating an object is dipped in a horizontal plane into a coating liquid and then removed and spun in a horizontal plane to remove excess liquid. A modified dip-spin coater uses a spindle that rotates the disk in a vertical plane. In this approach the edge of the disk is dipped into the coating fluid and rotated to coat the outermost portion of both sides of the disk. The disk is then removed from the coating fluid and spun in a vertical plane to remove excess coating fluid. See US Patent Publication 2004/0202793.
Roll coaters have been used primarily to coat flat surfaces.
In each of the forgoing the thin film has a flat surface which is coplanar with the flat surface of the object.
None of these prior art coaters are designed to uniformly coat the surfaces of objects that are more complex than a typical disk or flat surface. Accordingly, it is an object of the invention to provide coating systems and processes that are capable of coating objects having complex surfaces.